Colonoscopy is a widely used medical technique to screen the human large intestine (i.e., colon) for cancer precursors. When visualized during a colonoscopy, polyps and adenomas can be identified and inspected and, if necessary, removed or excised. However, parts of the colon surface may not be visualized during a colonoscopy, and it can be hard for the endoscopist to realize that portions were missed and the extent thereof from the colonoscopic video. Non-visualization can occur for multiple reasons, e.g., lack of orientations of the colonoscope to the full circumference of parts of the colon, occlusion from colon structures, and/or stool inside the colon.